1 /* 2 * 3 * Copyright 2017 gRPC authors. 4 * 5 * Licensed under the Apache License, Version 2.0 (the "License"); 6 * you may not use this file except in compliance with the License. 7 * You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 * 17 */ 18 19 #ifndef GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RETRY_THROTTLE_H 20 #define GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RETRY_THROTTLE_H 21 22 #include <grpc/support/port_platform.h> 23 24 #include "src/core/lib/gprpp/ref_counted.h" 25 26 namespace grpc_core { 27 namespace internal { 28 29 /// Tracks retry throttling data for an individual server name. 30 class ServerRetryThrottleData : public RefCounted<ServerRetryThrottleData> { 31 public: 32 ServerRetryThrottleData(intptr_t max_milli_tokens, intptr_t milli_token_ratio, 33 ServerRetryThrottleData* old_throttle_data); 34 35 /// Records a failure. Returns true if it's okay to send a retry. 36 bool RecordFailure(); 37 38 /// Records a success. 39 void RecordSuccess(); 40 41 intptr_t max_milli_tokens() const { return max_milli_tokens_; } 42 intptr_t milli_token_ratio() const { return milli_token_ratio_; } 43 44 private: 45 // So Delete() can call our private dtor. 46 template <typename T> 47 friend void grpc_core::Delete(T*); 48 49 ~ServerRetryThrottleData(); 50 51 void GetReplacementThrottleDataIfNeeded( 52 ServerRetryThrottleData** throttle_data); 53 54 const intptr_t max_milli_tokens_; 55 const intptr_t milli_token_ratio_; 56 gpr_atm milli_tokens_; 57 // A pointer to the replacement for this ServerRetryThrottleData entry. 58 // If non-nullptr, then this entry is stale and must not be used. 59 // We hold a reference to the replacement. 60 gpr_atm replacement_ = 0; 61 }; 62 63 /// Global map of server name to retry throttle data. 64 class ServerRetryThrottleMap { 65 public: 66 /// Initializes global map of failure data for each server name. 67 static void Init(); 68 /// Shuts down global map of failure data for each server name. 69 static void Shutdown(); 70 71 /// Returns the failure data for \a server_name, creating a new entry if 72 /// needed. 73 static RefCountedPtr<ServerRetryThrottleData> GetDataForServer( 74 const char* server_name, intptr_t max_milli_tokens, 75 intptr_t milli_token_ratio); 76 }; 77 78 } // namespace internal 79 } // namespace grpc_core 80 81 #endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_RETRY_THROTTLE_H */ 82
